PROTAC Mcl1 degrader-1 (compound C3), a proteolysis targeting chimera (PROTAC), is a potently and selectively Mcl-1 inhibitor with an IC50 of 0.78 μM. PROTAC Mcl1 degrader-1 induces the ubiquitination and proteasomal degradation of Mcl-1 by introducing the E3 ligase cereblon (CRBN)-binding ligand pomalidomide to Mcl-1 inhibitor S1-6 with μM-range affinity.